If your home has steel or timber frames, then cavities are needed to let moisture leave the building and the property is not suitable for cavity wall insulation.
Is cavity wall insulation good in older houses? While not all older properties are suitable for cavity wall insulation, it does have benefits for those that are. It can decrease costs and a home's carbon footprint while costing less than most other efficiency measures.
One of the main reasons as to why people decide to have their cavity wall insulation removed is because their property isn't suitable for it. For instance, if your property is often subject to wind-driven rain, then it is not recommended that a cavity wall is in place.
Homes built before 1929 all tend to have solid walls, as cavity walls had not been invented. Homes built between 1930 and 1939 may or may not have solid walls. This is when cavity walls were becoming more popular but not yet "the norm". Very few homes were built 1939 to 1945 due to the second world war.
While cavity walls are a popular build type across the UK, not all homes have these types of walls. Almost all pre-1920 properties in the UK are solid wall properties, of which a staggering 90% remain uninsulated according to the Solid Wall Insulation Guarantee Agency (SWIGA).
Houses built in the 1970s generally have cavity walls, but not all were constructed with insulation. Checking the EPC of a 1970s home can confirm if insulation was installed.
So, if it's exposed to wind-driven rain from the coast, it's more than likely to cause damp in your home, costing you more money than it's worth. If your home is timber, or steel framed, do not, I repeat, DO NOT have cavity wall insulation.
Cavity wall insulation usually lasts 25 years or more. Still, it may need replacement due to material degradation, moisture damage, structural changes, increased energy bills, or visible issues like dampness and mould.
In cases where the cavity is left open, moisture can condense into the loft to cause dampness and mould issues. Sometimes other measures like trickle vents for windows should be installed prior to installation to compensate for increased thermal efficiency.
People were warned that cavity wall insulation should not be fitted to homes that contain steel or wooden frames. This is due to any condensation that forms potentially causing corrosion to the metal and rotting in the timber.
Batts, blown-in, dense pack cellulose, open cell spray foam, and closed cell spray foam are all potential options for an older home. If you want to find out which combination of these is best for your house, contact a professional insulation contractor.
This is another symptom of your cavity wall insulation's deteriorating health. Your boiler and radiators are working overtime to try and warm your house up, the heat wants to escape, and your insulation is allowing it! If your insulation can't even hold itself up, then there's no chance of it holding your heat in.
It May Cause Property Damage
For example, in the case of bead cavity insulation, the materials are injected into the wall using an injection gun. This injection gun pushes the over-bonded beads into the cavity. That can add a lot of pressure to the walls, which can cause cracks.
Polystyrene Beads
You're probably familiar with these beads as package protection materials and bean bag fillers. Yet, they're the ideal cavity wall insulation. Polystyrene beads, or EPS, are made of a carbon polymer, which is a poor thermal conductor.
Most manufacturers offer a 25-year warranty, but the typical lifespan of cavity wall insulation is between 20-100 years. When installed correctly, cavity wall insulation is made to last the lifespan of your property. Unless damage occurs, all cavity wall insulation should last for up to a century.
The simplest way is to check your brickwork for drill holes. If you notice small, evenly spaced holes that have been filled in, this is a sign that cavity wall insulation is installed.
Moreover, the homes built before the 1980s had narrow cavities, which weren't suitable for insulation installation. Because of this, homeowners with old cavity wall insulation should consider removal and replacement to address health concerns and upgrade their insulation to modern materials.
For some early cavity walls, cavity fill insulation will always be unsuitable and the construction needs to be treated as a solid wall, insulated either internally or externally or not at all.
Check Your Wall Insulation Level
Remove the outlet cover and shine a flashlight into the crack around the outlet box. You should be able to see if there is insulation in the wall and possibly how thick it is. Pull out a small amount of insulation if needed to help determine the type of insulation.
Do cavity walls need air bricks? Yes, cavity walls need air bricks to maintain adequate ventilation and prevent moisture build-up. Air bricks help circulate air within the cavity, reducing the risk of condensation and dampness.
Solid brick wall construction
In England, houses built before the 1930s and older periods such as Victorian or Georgian will often have solid brick walls.
Cavity Wall Insulation has been mandatory since 1990, but as a fairly quick job for installers it hasn't always been done well.